摘要
近500次珠状及截头珠状硬质合金试头压入实验,已在实验室内完成。实验中使用了四种不同型号的硬质合金试头;0.0005(米/秒)、0.005(米/秒)、0.05(米/秒)和5(米/秒)四种凿入速度;10,000公斤和4,000公斤等多种作用力,以及干、湿两类花岗岩和砂岩试块。试验表明,当凿入速度低于0.05(米/秒)时,对于砂岩,φ14.3毫米的半球头珠状试头效果最好;对于花岗岩,φ10毫米的珠状试头,效果也最好。而截头珠状试头,当作用力小于单向压缩强度的11～13倍时,或侧向夹制性较大时,基本上不能破碎岩石。当加载速度提高到5(米/秒)后,在砂岩中,仍以φ14.3毫米的珠状试头效果最好;在花岗岩中,则截头珠状试头反居前列。此外,试验还表明,只是在低速加截潮湿的砂岩时,含水率才对岩石的破碎效果产生有利的影响。例如,比相应的干燥砂岩增加岩屑重量160～340%。岩屑粒度与比能之间则基本上不存在比例关系。
More than five hundred button indentation tests have been carried out in the laboratory of The University of LuLE,Sweden,on samples of dry and wet granite as well as sandstone.Four Kinds of button indenters with different geometrical factors; four levels of penetration rates-0.0005m/s,0.005m/s 0.05m/s and 5m/s;applied forces of different magnitude were used during these tests.The test results reveal that,when the penetration rate is lower than 0.05m/s,hemisphenical button indenters with a diameter of 14.3mm and 10mm gave best results for sandstone and granite respectively. At a penetration rate of 5m/s,the 14.3mm dia hemispherical button indenter rema- ined the optimum for sandstone,whereas the truncated hemispherical button indenter gave best results for granite.In addition the tests showed that only at low penetration rates does water content have a beneficial effect on rock fragmentation:for wet san- dstone,160%-340% more debris by weight was produced compared with corresponding tests on dry sandstone,due to the sandstone's high porosity and ability to contain water.There is no proportional relationship between specific energy and the debris particle size.
出处
《有色金属工程》
CAS
1981年第1期16-22,共7页
Nonferrous Metals Engineering
